drm/omap: Check omap_dss_device type based on the output_type field

Various functions that need to differentiate between omap_dss_device
instances corresponding to displays and to internal encoders use the
omap_dss_device.driver field, which is only set for display instances.
This gets in the way of the omap_dss_device operations refactoring.
Replace that with a check based on the output_type field which is set
for all omap_dss_device instances but displays.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/dss/base.c

@@ -164,7 +164,8 @@ struct omap_dss_device *omapdss_device_get_next(struct omap_dss_device *from,
 		 * Accept display entities if the display type is requested,
 		 * and output entities if the output type is requested.
 		 */
-		if ((type & OMAP_DSS_DEVICE_TYPE_DISPLAY) && dssdev->driver)
+		if ((type & OMAP_DSS_DEVICE_TYPE_DISPLAY) &&
+		    !dssdev->output_type)
 			goto done;
 		if ((type & OMAP_DSS_DEVICE_TYPE_OUTPUT) && dssdev->id &&
 		    dssdev->next)
@@ -223,7 +224,7 @@ void omapdss_device_disconnect(struct omap_dss_device *src,
 	dev_dbg(dst->dev, "disconnect\n");
 
 	if (!dst->id && !omapdss_device_is_connected(dst)) {
-		WARN_ON(!dst->driver);
+		WARN_ON(dst->output_type);
 		return;
 	}
 

drivers/gpu/drm/omapdrm/dss/omapdss.h

@@ -406,6 +406,12 @@ struct omap_dss_device {
 	unsigned int alias_id;
 
 	enum omap_display_type type;
+	/*
+	 * DSS output type that this device generates (for DSS internal devices)
+	 * or requires (for external encoders). Must be OMAP_DISPLAY_TYPE_NONE
+	 * for display devices (connectors and panels) and to non-zero value for
+	 * all other devices.
+	 */
 	enum omap_display_type output_type;
 
 	const char *name;